import {
  NativeEventEmitter,
  NativeModules,
  DeviceEventEmitter,
  Platform,
} from 'react-native';

type EventCallback = (info: any) => void;
type EventMap = { [key: string]: EventCallback };
const { RangersAppLogEmitter } = NativeModules;

const prefix = 'RangersAppLogEmitter_';
const subscriptionMap = new Map();

const isIOS = Platform.OS === 'ios';
let emitter: any = DeviceEventEmitter;
if (isIOS) {
  emitter = new NativeEventEmitter(RangersAppLogEmitter);
}

function bindEvent(eventName: string, callback: EventCallback) {
  if (!isIOS) {
    eventName = prefix + eventName;
  }
  const subscription = emitter.addListener(eventName, callback);
  subscriptionMap.set(eventName, subscription);
}

function unbindEvent(eventName: string) {
  if (!isIOS) {
    eventName = prefix + eventName;
  }
  const subscription = subscriptionMap.get(eventName);
  if (subscription) {
    subscription.remove();
  }
}

const eventEmitter = {
  bindEvents(eventMap: EventMap) {
    Object.keys(eventMap).forEach((key) => {
      bindEvent(key, eventMap[key]);
    });
    RangersAppLogEmitter.connect();
  },
  unbindEvents(...eventNames: string[]) {
    eventNames.forEach((eventName) => {
      unbindEvent(eventName);
    });
  },
};

export default eventEmitter;